The present invention relates to a process for producing hollow plastic receptacles. Each half of the receptacle is formed from two portions of a starting material strip, preferably two portions of a tube, or the entire receptacle is formed from a tube. When two receptacle halves are formed, the halves are welded together to complete the receptacles. Outside of at least part of one of the seams, a marginal piece of waste zone or segment is formed with at least one hollow body.
In the known method of forming hollow plastic receptacles by blow molding, a tube or hose is pressed together, as much as possible in the area of the margin of the receptacles for the purpose of cooling. In this margin, the pressure causes a fusion of the two layers. To decrease the closing forces of the molding tool required for this purpose, it was proposed to provide the margin with parallel ribs by means of corresponding recesses in the area of the molding tool forming the edge or marginal zone.
An object of the present invention is to provide a process for making hollow plastic receptacles where the formed receptacles are reinforced.
Another object of the present invention is to provide a process for making hollow plastic receptacles with at least one hollow body in a marginal area.
The foregoing objects are obtained by a process for producing hollow plastic receptacles, comprising the steps of: forming at least one hollow receptacle from a member of heat-sealable plastic, forming fused seams on marginal portions of the member to provide at least one marginal waste segment along the fused seams, and forming at least one hollow body in the marginal waste segment.
The shape and size of the hollow body or bodies can be adapted to whatever is required. Thus, it is generally advantageous to manufacture hollow bodies of different shapes and/or sizes.
If a plurality of adjacently arranged, flat or bottle-like receptacles (for instance, ampules), are produced simultaneously, and if each of the receptacles has a neck and/or head portion adjacent the body, then at least one hollow body can be formed from the area between two adjacent neck and/or head portions.
In order not to increase the cycle time by the formation of the hollow body or bodies, the formation and the fusion of each hollow body preferably occur simultaneously with the formation or fusion welding of the receptacle or receptacles.
Each receptacle produced can be filled following the fusion welding of both of its halves, if the halves are formed separately, and can be closed after filling in a second fusion welding operation.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.